IOError communicating with dropbot-dx board after plugin is enabled

[cfobel]

Set up

Hardware set up:

• DropBot v2.0 control board connected via USB
• dropbot-dx Teensy board connected via USB

Enable selected for the following plugins:

• dmf_control_board_plugin==2.2.13
• dropbot_dx_accessories==2.1.62

Attempt following steps:

1. Enable dmf_control_board_plugin
   1. Connect DMFControlBoard() instance.
2. Enable dropbot_dx_accessories
   1. Connect dropbot_dx.SerialProxy() instance.
   2. Try to read temperature/humidity from sensor over i2c bus through dropbot-dx board.

Expected behaviour

• Successful connection to DMFControlBoard
• Successful connection to dropbot_dx.SerialProxy
• Successful read of temperature/humidity from sensor over i2c bus through dropbot-dx board.

Observed behaviour

• Successful connection to DMFControlBoard
• Successful connection to dropbot_dx.SerialProxy
• Attempt to read temperature/humidity from sensor over i2c bus through dropbot-dx board causes dropbot-dx board to become unresponsive.

Once the dropbot-dx board becomes unresponsive, any further attempted communication with the board (e.g., setting the state of the magnet upon entering real-time mode) causes errors like:

Attempting to launch the DropBot DX configuration dialog like:

results in the following exception:

Reason: Timed out waiting for response.
2017-01-04 10:45:55 [INFO:root]: Traceback (most recent call last):
  File "C:\Users\MR-BOX2\MicroDrop\lib\site-packages\microdrop\plugin_manager.py", line 223, in emit_signal
    return_codes[observer.name] = f(*args)
  File "C:\Users\MR-BOX2\Documents\MicroDrop\plugins\dropbot_dx_accessories_plugin\__init__.py", line 568, in on_step_run
    self.dropbot_dx_remote.light_enabled = not options['dstat_enabled']
  File "C:\Users\MR-BOX2\MicroDrop\lib\site-packages\dropbot_dx\proxy.py", line 116, in light_enabled
    self.update_state(light_enabled=value)
  File "C:\Users\MR-BOX2\MicroDrop\lib\site-packages\base_node_rpc\proxy.py", line 369, in update_state
    return super(StateMixinBase, self).update_state(state)
  File "C:\Users\MR-BOX2\MicroDrop\lib\site-packages\dropbot_dx\node.py", line 1012, in update_state
    response = self._send_command(packet)
  File "C:\Users\MR-BOX2\MicroDrop\lib\site-packages\base_node_rpc\proxy.py", line 134, in _send_command
    result = self._read_response()
  File "C:\Users\MR-BOX2\MicroDrop\lib\site-packages\base_node_rpc\proxy.py", line 145, in _read_response
    raise IOError('Timed out waiting for response.')
IOError: Timed out waiting for response.

[cfobel]

Unresponsive behaviour can be avoided by attempting to read the temperature sensor using the DropBot v2.0 control board first, i.e.:

        # If the DropBot v2.0 control board plugin is loaded and the DropBot
        # v2.0 control board is connected, try to read temperature/humidity
        # over i2c through control board.
        try:
            service = get_service_instance_by_name('wheelerlab.dmf_control_board_plugin')
        except KeyError:
            pass
        else:
            if service.enabled() and service.control_board.connected():
                try:
                    env = self.get_environment_state(service.control_board).to_dict()
                    logger.info('temp=%.1fC, Rel. humidity=%.1f%%' %
                                (env['temperature_celsius'],
                                 100 * env['relative_humidity']))
                    self.has_environment_data = True
                    self.environment_sensor_master = service.control_board
                except:
                    pass

        # If temperature/humidity has not been read (e.g., DropBot v2.0 control
        # board plugin not loaded) try to read temperature/humidity over i2c
        # through **DropBot DX** board.
        if not self.has_environment_data:
            try:
                env = self.get_environment_state(self.dropbot_dx_remote).to_dict()
                logger.info('temp=%.1fC, Rel. humidity=%.1f%%' %
                            (env['temperature_celsius'],
                             100 * env['relative_humidity']))
                self.has_environment_data = True
                self.environment_sensor_master = self.dropbot_dx_remote
            except:
                pass

        # Get instrument identifier, if available.
        self.dropbot_dx_id = getattr(self.dropbot_dx_remote, 'id', None)

Verified plugin:

dropbot_dx_accessories_plugin.zip